Key to the major classes of Larger Fungi

• Spores borne externally on stalks on a clavate to cylindrical cell Basidiomycotina
• Spores produced within a clavate, cylindrical or subglobose cell Ascomycotina

Key to major groups based on character of basidium and fruit-body shape

• 1. Basidia either produced in a hymenium or in a mass, and until maturity contained within a closed fruit-body Gasteromycetes
• Basidia produced in a layer of cells (hymenium) and exposed to the air before the maturity of the spores (Hymenomycetes) 2
• 2. Basidia simple, a single cell (fig. 5) (Homobasidiae) 3
• Basidia usually septate, or if simple then fruit-body gelatinous and often collapsing to form a skin when dried (Heterobasidiae) 4
• 3. Fruit-body usually fleshy, soft and easily decaying (putrescent), hymenium spread over the surface of gills, ridges or within tubes Agaricales (p. 22)
• Fruit-body with hymenium smooth or spread-out on teeth, ridges or plates or if within tubes then fruit-body tough and leathery Aphyllophorales (p. 135)
• 4. Basidia divided 5
• Basidia simple and apex drawn out into two long necks Plate 61 (p. 185) Dacrymycetales (p. 180)
• 5. Basidia divided transversely by one to three horizontal septae Plate 60 (p. 183) Auriculariales (p. 182)
• Basidia divided into two or four cells by vertical septae Plate 61 (p. 185) Tremellales (p. 184)